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Meet the Multiverse October 28, 2012

According to Goldilocks, Little Bear’s porridge was ‘just right’, but only in the last 60 years or so have scientists been forced to agree. Not just about porridge, of course, but about planet earth’s apparently unique capacity to sustain life.

The realisation that earth is perfectly suited (‘just right’) for the task of playing host to intelligent life has led scientists to call it ‘the Goldilocks planet’. Logically, of course, it should be called the porridge planet, since it was the porridge rather than Goldilocks that was just right, but that’s a detail. Exploration of the solar system has demonstrated the total uniqueness of earth among the otherwise barren solar planets.

Neither too hot nor too cold; provided with an abundance of water; enjoying a non-toxic, life-promoting atmosphere; protected from harmful radiation by its magnetic field; and with just the right gravitation to retain its atmosphere without squashing its inhabitants, Earth provides a perfect haven for life. An estate agent couldn’t write a more glowing specification.

Fine-tuned universe

But that’s only the beginning. It isn’t just earth that seems specially designed to support life, but the universe as a whole. In 1999, Sir Martin Rees (then Astronomer Royal) published a book entitled Just six numbers — the deep forces that shape the universe1, in which he explains that certain physical constants that crop up in the laws of nature have to be precisely what they are (within very close limits) to allow life to exist and flourish anywhere in the universe.

In other words, these numbers are ‘fine-tuned’ to allow life to exist. He writes; ‘This book describes six numbers that now seem especially significant. Two of them relate to the basic forces [in nature]; two fix the size and overall “texture” of our universe and determine whether it will continue for ever; and two more fix the properties of space itself. … if any one of them were to be ‘untuned’ [from their precise values] there would be no stars and no life’2.

The late astronomer Sir Fred Hoyle FRS put it more bluntly: ‘A common sense interpretation of the facts suggests that a super intellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature … The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question’3.

Universes galore

In spite of Hoyle’s reputation as a scientist — and even though his opinion was so strongly expressed and he had no religious axe to grind — most leading scientists firmly reject the idea that the universe was designed. Why? Because the only qualified designer would be God himself and when it comes to explaining the natural world, they won’t allow God a foot in the door. In Just six numbers, Martin Rees illustrates this bias as follows: ‘Is this [fine] tuning just a brute fact, a coincidence? Or is it the providence of a benign Creator? I take the view that it is neither. An infinity of other universes may well exist where the numbers are different’. Meet the multiverse — the name given to the huge (though not necessarily infinite) array of hypothesised universes which Rees says ‘may well exist’. Let’s call the multiverse ‘MV’ for short.

Professor David Deutsch is a physicist and author of a book entitled The fabric of reality. Commenting on his ideas, popular-science writer John Gribben declares, ‘Deutsch is completely convinced of the reality of the Multiverse … He accepts that there is, for example, a vast array of universes with different versions of himself in them, so that in some he is (not “might be” but really is) a professor in Cambridge instead of working in Oxford, while in others he is not a scientist at all’4. Gribben isn’t being funny; he is himself quite convinced that the MV is real. Admittedly, neither Deutsch nor Gribben can see, hear or communicate with their multiversal cousins. Indeed, these doppelgangers are utterly undetectable and unknowable. But that doesn’t seem to dampen the current enthusiasm for MVs. Their promotion by leading scientists like Sir Martin Rees and Stephen Hawking convinces many that the MVs must surely be there — perhaps only millimetres away from one another in multi-dimensional space, like so many snapshots stacked one upon another.

‘Get-out-of-jail-free’

But must we accept what these experts say? Actually, no! The MV concept is a bit like a ‘get-out-of-jail-free’ card in the game of Monopoly — an easy escape route from various difficulties and implications thrown up by modern physics and cosmology. Instead of struggling with the intransigent realities of the one universe we actually know to exist, it’s often much easier to wave them away by appealing to the MV.

It intrigues me that some of the MV’s greatest enthusiasts accuse theists of appealing to a ‘God of the gaps’ to account for things that science cannot explain — while at the same time claiming that the MV is a great way to explain otherwise inexplicable observations. In reality, the MV is the ultimate ‘speculation-of-the-gaps’, being almost by definition that which lies beyond the reach of science.

Is the MV scientific?

This last statement will be challenged, and there have been ingenious suggestions concerning ways to test the MV concept scientifically. It would take too long to explain and refute these ideas here, so let me offer one simple reason why the MV (even if it existed) could never be detected by scientific experiments.

One of the chief selling points of the MV is that the laws of nature must be different in the different universes that make it up. The MV loses most of its appeal (and indeed purpose) if all those other universes work (scientifically speaking) in the same way as our own. Yet the only science known to man is that which explores and describes the universe in which we actually live. Our own ‘local’ science cannot (again by definition) be used to investigate or even recognise alleged universes which operate on different principles and according to different laws of nature. Any such exo-universe remains firmly beyond the reach of science as we know it.

Why invoke the MV?

So why would anyone embrace such a bizarre idea as the MV in the first place? As I argue in my book Who made God?5 scientific explanations often lead us into conceptual quagmires. For example, Einstein’s general theory of relativity provides a magnificent explanation of gravitational phenomena, but only at the expense of introducing ‘warped’ space and time — things that most of us can’t get our heads around. Another example is quantum mechanics (QM). This theory is highly successful in describing atomic-scale events, but involves some very strange ideas — like a particle (such as an electron) being in two different places at the same time; that is, until you look at it and find it in one place or the other.

Some versions of the MV try to explain away such ‘contradictions’ of QM by saying that the particle does still exist in the other place, but in a different universe. This is the ‘many worlds’ hypothesis which removes the contradiction, but only at the expense of creating a new universe almost every time an atomic event takes place. That would mean that billions of new universes have been created since you started reading this sentence. Appealing to a MV to explain things we don’t understand about QM strikes me as an act of desperation, and that brings me back to the fine-tuning of the universe.

Take your choice

Why is the universe hospitable to life? There can be only three answers: (1) this is a brute fact and impossible to explain; (2) the universe was made this way by an intelligent Creator; and (3) there exist a vast number of different universes, one of which by chance has just the right properties to support intelligent life.

The first of these answers is no answer at all, since it simply says that no answer exists. The second is immortalised in the opening words of the Judaeo-Christian Bible, ‘In the beginning God created the heavens and the earth’. The third answer is nothing more than an attempt to avoid the implications of answer (2).

For if we really are the products of a Creator, then we must have some relationship to him and some responsibility towards him. Indeed, the Bible goes further and says that, ‘He gives to all, life and breath and all things … so that [we] should seek the Lord … and find him, though he is not far from each one of us, for in him we live and move and have our being’ (Acts 17:25-28). Now that, to me, is an answer that makes sense!

References:

1. Martin Rees, Just six numbers, Basic Books, 2000

2. Just six numbers, p.4

3. Fred Hoyle, Engineering and Science, 11/81, pp. 8-12

4. John Gribbin, In search of the multiverse (Penguin Books, 2010) p.62

5. Edgar Andrews, Who made God? Searching for a theory of everything (EP Books, 2009)